JPH07180643A - Ignition timing control device for internal combustion engine - Google Patents

Abstract

PURPOSE:To provide an ignition timing control device for an internal combustion engine executing ignition timing delay correction for the prevention of transient knocking at the accelerating time, taking account of the operating state of the engine. CONSTITUTION:An ignition timing control device for an internal combustion engine has an ignition timing control means 101 for adjusting the ignition timing of the engine, and a transient delay control means 102 for setting (105) the transient delay quantity for the delay correction of ignition timing at the accelerating time (103) of the engine. In this case, the transient delay control means 102 estimates the intake air temperature from the operating state of the engine before acceleration to change (104) the transient delay quantity.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ignition timing control device for an internal combustion engine, and more particularly to an ignition timing control device for an internal combustion engine which performs retard correction for preventing knocking.

[0002]

Knocking in an internal combustion engine is a phenomenon in which the air-fuel mixture in a combustion chamber self-ignites and impulsively burns without waiting for the propagation of a flame ignited by an ignition plug. If this phenomenon continues, ignition occurs. The electrodes of the plug and the piston may be overheated and melted, resulting in damage to the engine. There is a close relationship between knocking and ignition timing, and if the ignition timing is advanced, the maximum combustion pressure rises and self-ignition occurs. In general, the ignition timing at which the maximum torque is extracted from the engine is in the vicinity of before and after the ignition timing at which knocking starts to occur, and it is most advantageous in terms of output and fuel efficiency to operate the engine in the boundary region where slight knocking appears and disappears. .

Therefore, the vibration of the cylinder block of the engine is detected by the knock sensor, and the number of detection output peak values exceeding the reference value is counted during a fixed period after engine ignition, that is, during the knock determination period, and the knocking is detected. Strength judgment,
A knock control system KCS has been implemented which corrects the ignition timing retard according to the knock intensity. But,
Since this KCS is not effective for knocking that occurs during transition such as acceleration, that is, transient knock, it is necessary to perform retard correction of the ignition timing for preventing transient knock based on the determination of the transient state. ing.

Regarding the ignition timing retard correction for preventing transient knock during acceleration, the transient knock during acceleration is caused by the lean air-fuel ratio due to the response delay of the fuel supply in the initial stage of acceleration. Since the lean tendency varies depending on the degree of acceleration and the vaporization rate of the air-fuel mixture related to the temperature of the engine, the ignition timing retard correction amount (hereinafter, also simply referred to as ignition retard amount). There is a circumstance that it cannot be set uniformly. Therefore, it has been proposed to effectively prevent transient knock by increasing the ignition retard amount during acceleration when the cooling water temperature of the engine is low and increasing it when the cooling water temperature is high. 63-2
Japanese Patent No. 46472).

[0005]

However, the transient knock at the time of acceleration is influenced by the intake air temperature as well as the cooling water temperature which almost corresponds to the combustion room temperature of the engine. In the above proposed technique, the intake air temperature is changed by the high cooling water temperature. There is a problem in that it is not possible to prevent the occurrence of knocking due to the rise of the. In order to deal with this, even if the intake air temperature is measured and the ignition retard amount is added, a temperature sensor for measuring the intake air temperature is required, which causes a problem of cost increase.

Therefore, an object of the present invention is to provide an ignition timing control device for an internal combustion engine, which executes ignition timing retard correction for preventing transient knock at the time of acceleration in consideration of the influence of intake air temperature as well as cooling water temperature. To do. Further, the present invention provides an ignition timing control device for an internal combustion engine, which executes ignition timing retard correction for preventing transient knock at the time of acceleration in consideration of the influence of the intake temperature as well as the cooling water temperature without using an intake temperature sensor. The purpose is to do.

A further object of the present invention is to provide an ignition timing control device for an internal combustion engine, which executes ignition timing retard correction for preventing transient knock during acceleration in consideration of the operating state of the engine.

[0008]

FIG. 1 is a block diagram showing a conceptual configuration of an ignition timing control device for an internal combustion engine according to the present invention. The ignition timing control device for an internal combustion engine according to the present invention is provided with an ignition timing for an engine. Timing control means 101 for adjusting
And its ignition timing during engine acceleration (acceleration determination function 10
In the ignition timing control device for the internal combustion engine, which has the transient retard angle control means 102 for setting the transient retard angle amount for the retard angle correction (transient retard angle amount setting function 105) in 3), The intake air temperature is estimated from the operating state of the engine before acceleration to change the transient retardation amount (intake air temperature estimating function 104).

In this case, the transient retard control means controls to increase the transient retard amount when the vehicle is at a low vehicle speed, or to increase the transient retard amount when the engine speed is low. .

[0010]

According to this structure, the influence of the engine cooling water temperature on the intake air temperature can be estimated from the operating state of the engine, and in addition to the high water temperature, the occurrence of transient knock due to the high intake air temperature can be prevented. .

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 2 is a conceptual configuration diagram showing a schematic configuration of an example of a structure of an internal combustion engine to which an ignition timing control device for an internal combustion engine according to the present invention is applied and a control system thereof. In the figure, 1 is an air filter, 2 is an air flow meter, 3 is a throttle valve, 4 is an opening detection sensor for the throttle valve 3, and 5 is a throttle valve.
Is an intake pressure (PM) sensor, 6 is a fuel injection valve, 7 is a cooling water temperature (THW) sensor, 8 is an air-fuel ratio sensor, and each of these sensors is an engine block 10, an intake pipe 11, an intake valve. Various corresponding operating condition parameters are detected from each part of the internal combustion engine including 11 ', the exhaust pipe 12, the exhaust valve 12', the piston 13, and the spark plug 14 and input to the control device 100. The knock sensor 9 is attached to the engine block 10, detects the vibration of the engine block 10, determines the knock intensity in the knock detection circuit 21, and inputs the knock determination result KS to the control device 100.

In addition to the various operating condition parameter meters and knock determination results described above, the control device 100 includes parameters such as an engine speed NE, a vehicle speed SPD, crank angle data CA, and an idle switch signal (not shown). Is also taken into consideration, the calculation and processing for fuel injection control and ignition timing control necessary for the operation of the engine are executed, the fuel injection valve 6 is controlled according to the result, and the spark plug 14 is operated via the ignition device 20. To control. Figure 3
3 is a flowchart showing a main routine of software executed in the control device 100 to realize the control, and this main routine is executed every predetermined crank angle, for example, 360 ° CA. In this main routine, various operating state parameters of the engine are taken in at step 101, a fuel injection control routine for performing calculations and processing required for fuel injection control is executed at step 102, and necessary for ignition timing control at step 103. An ignition timing control routine for performing calculation and processing is executed and the processing ends.

FIG. 4 is a software for realizing the embodiment of the ignition timing control apparatus for the internal combustion engine according to the present invention, in which the "transient retard angle control" control for retarding the ignition timing to prevent transient knock is performed. It is a flowchart which shows the routine which sets a start condition. The control start condition setting routine is executed by interrupting the main routine of FIG. 3 at regular intervals of, for example, 1 sec. First, in step 201, the idle duration counting counter CIDL is determined. In this embodiment, CIDL
Is, for example, 180 seconds or more (CIDL ≧ 1
80 sec) is judged. If it is 180 seconds or more (Y), the process proceeds to step 202 to set the flag XATRNA, and if it is less than 180 sec (N), the flag XATRNA is reset in step 203.

FIG. 5 is a flow chart showing the control routine of the idle duration counting counter CIDL necessary for the transient retard control in the software for realizing the embodiment of the ignition timing control apparatus for the internal combustion engine according to the present invention. This routine is executed every 1 sec. First, in step 301, the cooling water temperature THW is determined. If the water temperature is 85 ° C. or higher (Y), the process proceeds to step 302, but if it is lower than 85 ° C. (N), CIDL is reset in step 306. In step 302,
The vehicle speed is determined by the vehicle speed sensor signal SPD and 3 km /
If less than h (Y), the process proceeds to step 303. 3 km /
If h or more (N), it is determined that the vehicle is running, and step 30 is performed.
At 6, the CIDL is reset. In step 303, the idle switch signal XIDL is used to determine whether the idle state is established. If it is in the idle state (Y), CIDL is incremented in step 304. If it is not in the idle state (N), CIDL is held in step 305.

Therefore, in the routines shown in FIGS. 4 and 5, if the water temperature is 85 ° C. or higher, the vehicle is stopped, and the vehicle is idle, the CIDL is incremented, and when the CIDL becomes 180 seconds or more, the intake air temperature becomes high. Therefore, the flag XATRNA is set, and the transient knocking occurrence state is determined. Then, when the water temperature is lower than 85 ° C., the transient knock is not likely to occur, and the CIDL is reset. Further, even when the vehicle is in a traveling state, the intake air is cooled by the vehicle speed air flow, so that transient knock is less likely to occur, and therefore the CIDL is reset. Further, even when the water temperature is 85 ° C. or higher and the vehicle is stopped, unless the engine is in the idle state, the intake air amount increases and the intake air temperature decreases, so that transient knock is less likely to occur. However, since the intake air temperature rises immediately when the engine enters the idle state (XIDL = 1), CIDL is held without being reset.

FIG. 6 is a flow chart showing a transient time determination and transient retard angle control routine in software for realizing the embodiment of the ignition timing control apparatus for the internal combustion engine according to the present invention. This routine is the main routine of FIG. It is incorporated into an ignition timing control routine in the routine, or is interrupted and executed at a predetermined crank angle or every predetermined time. First, in step 401,
Determine the current intake pipe pressure (PM ≧ 320 mmHg
? ), When PM is 320 mmHg or more, it is determined that the intake amount is large and knocking is likely to occur (Y),
Go to step 402. When it is less than 320 mmHg (N), in step 406, the transient retard angle amount ATRN
The initial value of is set to 0 ° CA, and the transient retard control is not executed.

In step 402, the previous PM value
(PM_i-1) And the current PM value (PM _i) And (P
M_i-1-PM_i≧ 80mmHg? ), A constant value, for example,
If it is higher than 80 mmHg (Y), PM will rise rapidly.
Therefore, it is judged to be in a transient state and the process proceeds to step 403. So
Otherwise (N), in step 406, the transition delay
The initial value of the angular amount ATRN is set to 0 ° CA, and the delay angle control during transition is performed.
Do not run. In step 403, the transient of FIG.
The flag set in the retard control start condition setting routine
Look at the state of lag XATRNA (XATRNA = 1
? ), If XATRNA = 1 (Y), step 404
At (A + 3) ° CA as the initial value of ATRN
And if XATRNA ≠ 1 (N), step
In step 405, A ° CA is set as the initial value of ATRN.
To put.

In this way, when the load is not high,
When the load is high but not in the accelerating state, the retard angle control during the transition is not performed (step 406), and in the high load and the normal accelerating state, the normal acceleration retard angle (A) control is performed (step 405). ) Then, under the condition of high load and acceleration and the intake air temperature is high, the retard amount is increased from the normal acceleration retard angle (A + 3) to prevent transient knock (step 404). ). FIG. 7 shows the transient retard amount ATR.
It is a characteristic view showing a control mode of N, and a normal transient retardation amount A
Although TRN decreases with time, the transient retard amount ATRN under the condition that the intake air temperature is high is increased and is executed for a longer time.

In the above-described embodiment, the control routine for executing the transient retard control after the cold start is explained, but the process at the warm start, that is, the restart is added. You can FIG. 8 is a flowchart showing a modified example of the routine for setting the transient retarding control start condition in which the process for restarting is added to the transient retarding control start condition determining routine of FIG. First, in step 501, it is determined whether or not the engine is restarted, for example, according to a determination item such as whether the engine is started after idling or is started within a predetermined time after the traveling is stopped. If it is not a restart (N), the routine proceeds to step 504, where the transient retardation control start condition determination routine at the time of cold start and the control routine of the counter CIDL of FIG. Executes transient retard control. If restarting (Y), it is determined in step 502 whether the water temperature THW is 90 ° C. or higher (THW ≧ 90 ° C.).
? ), If it is lower than 90 ° C. (N), the process proceeds to step 504, and the cold start retard control is started. If it is 90 ° C. or higher (Y), the transient retard angle control flag XATRNA is set to 1 and
The retard control routine of FIG. 6 is executed to carry out the required retard control.

Further, as described above, the transient retard control according to the present invention is designed to correct the influence of the water temperature on the intake air temperature in consideration of the operating condition. In this case, the transient retard amount is adjusted to the operating condition. Can be changed to prevent transient knock more effectively. That is, for example, when the vehicle speed is low, the temperature in the engine room of the engine becomes high,
Since the intake air temperature rises more easily, it is effective to increase the transient retardation amount. Further, even when the engine speed is low, that is, when the engine is running at low speed, the temperature in the engine room does not easily decrease, so it is effective to increase the transient retardation amount.

In short, it is considered that the intake air temperature, which is one of the factors of the transient knock, changes depending on the balance between the temperature of the engine body and the ventilation amount of air in the engine room. It can be noted that the intake air temperature is unlikely to rise when the ventilation volume of air in the room is large. For example, when the vehicle is running at high speed, the ventilation volume increases due to the running wind, and even when the engine is rotating at high speed, air is taken into the engine room early, so the air in the engine room is rapidly discharged. It will be replaced. Therefore, in such an operating state of the engine, it is determined that the rise in intake air temperature is not so large, and even if the transient retard angle control for preventing transient knock is reduced, transient knock does not easily occur. .

Therefore, based on this point of view,
For example, it is more appropriate to use the maps of engine load and vehicle speed, engine load and engine speed, etc., to set the above-mentioned transient retard amount for transient knock prevention more finely according to the operating state of the engine. It is possible to realize a simple transient retard control.

[0023]

As described above, according to the ignition timing control system for an internal combustion engine of the present invention, the influence of the cooling water temperature of the engine on the intake air temperature is corrected in consideration of the operating state of the engine. Optimal ignition timing correction during transients is possible without the need for a new intake air temperature sensor, and
An inexpensive countermeasure against transient knock when the intake air temperature rises is realized.

[Brief description of drawings]

FIG. 1 is a block diagram showing a conceptual configuration of an ignition timing control device for an internal combustion engine according to the present invention.

FIG. 2 is a conceptual configuration diagram showing a schematic configuration of an example of a structure of an internal combustion engine to which an ignition timing control device for an internal combustion engine according to the present invention is applied and a control system thereof.

FIG. 3 is a flowchart showing a main routine of software executed in a control device to realize fuel injection control and ignition timing control necessary for operating the engine.

FIG. 4 is a flowchart showing a routine for setting a start condition for transient retardation control in software for implementing an embodiment of an ignition timing control device for an internal combustion engine according to the present invention.

FIG. 5 is a flowchart showing a control routine of an idle duration counting counter CIDL required for transient retardation control in software for implementing an embodiment of an ignition timing control device for an internal combustion engine according to the present invention.

FIG. 6 is a flowchart showing a transient determination and transient retard control routine in software for implementing an embodiment of an ignition timing control device for an internal combustion engine according to the present invention.

FIG. 7 is a characteristic diagram showing a control mode of a transient retard angle ATRN.

FIG. 8 is a flowchart showing a modified example of a routine for setting a transitional retard control start condition.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Air filter 2 ... Air flow meter 3 ... Throttle valve 4 ... Throttle valve opening detection sensor 5 ... Intake pressure (PM) sensor 6 ... Fuel injection valve 7 ... Cooling water temperature (THW) sensor 8 ... Air-fuel ratio sensor 10 ... Engine block 11 ... Intake pipe 11 11 '... Intake valve 12 ... Exhaust pipe 12' ... Exhaust valve 13 ... Piston 14 ... Spark plug 100 ... Control device 20 ... Ignition device 21 ... Knock detection circuit 100 ... Control device 101 ... Ignition timing control means 102 ... transient retard angle control means 103 ... acceleration determination function 104 ... intake air temperature estimation function 105 ... transient retard angle amount setting function

Claims (3)

[Claims] 1. Ignition timing control means for adjusting the ignition timing of the engine, and transient retardation control means for setting a transient retardation amount for retarding the ignition timing in the ignition timing control means during acceleration of the engine. In the ignition timing control device for an internal combustion engine, the transient retard control means estimates the intake air temperature from the operating state of the engine before acceleration, and changes the transient retard amount. Timing control device. 2. The ignition timing control device for an internal combustion engine according to claim 1, wherein the transient retard control means increases the transient retard amount when the vehicle is at a low vehicle speed. apparatus. 3. The ignition timing control device for an internal combustion engine according to claim 1, wherein the transient retard control means increases the transient retard amount when the engine speed is low. Ignition timing control device.